It is a GOOD_THING to check the return value from fclose(), as some operating systems only flush file output on close, and can, therefore, return an error from fclose(). You can catch severe data-eating errors by doing this.

It is very important to make sure you clear any incoming packets out of the incoming buffer using fread() or some equivalent. Although you can call fclose() the socket does not actually shut down until the inbound packets have been cleared. This can lead to some confusion.

Generally, it's always a good idea to close a file when you're done with it. It's very easy for something to go wrong and corrupt a file that hasn't been closed properly. If you're concerned about efficiency, the overhead is negligible.

Trying to understand how 'end foreach' and 'endwhile' differ, I've encountered a problem I can't solve by myself. The following is a fairly easy stock portfolio script. Everything works, except at the end where I want to calculate the average of the gains as represented by $gain[$i].